1. Field of the Invention
This invention is directed to protein patterning on implantable devices, such as drug delivery vascular stents, for accelerated healing.
2. Description of the State of the Art
Percutaneous coronary intervention (PCI) is a procedure for treating heart disease. A catheter assembly having a balloon portion is introduced percutaneously into the cardiovascular system of a patient via the brachial or femoral artery. The catheter assembly is advanced through the coronary vasculature until the balloon portion is positioned across the occlusive lesion. Once in position across the lesion, the balloon is inflated to a predetermined size to radially compress against the atherosclerotic plaque of the lesion to remodel the lumen wall. The balloon is then deflated to a smaller profile to allow the catheter to be withdrawn from the patient's vasculature.
A problem associated with the above procedure includes formation of intimal flaps or torn arterial linings which can collapse and occlude the conduit after the balloon is deflated. Moreover, thrombosis and restenosis of the artery may develop over several months after the procedure, which may require another angioplasty procedure or a surgical by-pass operation. To reduce the partial or total occlusion of the artery by the collapse of arterial lining and to reduce the chance of the development of thrombosis and restenosis, a stent is implanted in the lumen to maintain the vascular patency.
The introduction of drug delivery stents has reduced the incidence of in-stent restenosis (ISR) after PCI (see, e.g., Serruys, P. W., et al., J.Am.Coll.Cardiol. 39:393-399 (2002)), which has represented the Achilles heel of interventional cardiology for more than one decade. However, ISR still poses a significant problem given the large volume of coronary interventions and expanding indications. The pathophysiology of ISR constitutes a complex interaction between cellular and acellular elements of the vessel wall and the blood. The loss of endothelial integrity after PCI constitutes a major factor for the development of ISR (see, e.g., Kipshidze, N., et al., J.Am.Coil.Cardiol. 44:733-739 (2004)).
The embodiments of the present invention address these concerns as well as others that are apparent by one having ordinary skill in the art.